Return Value

// Add the following directive to the file: // using System.Linq.Expressions; // A label expression of the void type that is the target for Expression.Return().
LabelTarget returnTarget = Expression.Label();
// This block contains a GotoExpression that represents a return statement with no value. // It transfers execution to a label expression that is initialized with the same LabelTarget as the GotoExpression. // The types of the GotoExpression, label expression, and LabelTarget must match.
BlockExpression blockExpr =
Expression.Block(
Expression.Call(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }), Expression.Constant("Return")),
Expression.Return(returnTarget),
Expression.Call(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }), Expression.Constant("Other Work")),
Expression.Label(returnTarget)
);
// The following statement first creates an expression tree, // then compiles it, and then runs it.
Expression.Lambda<Action>(blockExpr).Compile()();
// This code example produces the following output: // // Return // "Other Work" is not printed because // the Return expression transfers execution from Expression.Return(returnTarget) // to Expression.Label(returnTarget).